A tax return for someone under the age of 16 cannot be e-filed. If the federal tax return cannot be e-filed then the state return cannot be e-filed. Both tax returns have to be printed and mailed.
See this TurboTax support FAQ for the procedure to print and mail tax returns - https://ttlc.intuit.com/questions/1944348-how-do-i-print-and-mail-my-return-in-turbotax-online
